1. Field of the Invention
The present invention relates to a device adapted to detachably clamp a die to a lower portion of a head unit of a blow moulding machine.
2. Description of the Prior Art
The inventor of the present invention knows the following prior art.
As shown in FIG. 8, an annular mounting block 73 is connected to a lower portion of a head unit 71 of a blow moulding machine and a receiving hole 84 is formed in a lower surface 73a of the block 73. A flange 85 provided in an upper portion of a die 75 is adapted to be snugly inserted into the receiving hole 84 from below. The flange 85 is fixedly secured to the block 73 by means of an annular pressing flange 93 and pressing bolts 94.
Generally, metal mould sets: comprising the die 75 and mandrels 81 are replaced two or three times a day.
In the above-mentioned conventional construction, when the die 75 is replaced many pressing bolts 94 and the pressing flange 93 of a large diameter must be removed and then replaced again. Therefore, replacing the die is difficult. In the case of a large blow moulding machine, since the pressing flange 93 is large and heavy, a loading and unloading machine such as a forklift, a crane or the like is needed for handling the pressing flange 93. Accordingly, handling the pressing flange is very difficult.